A counting sensor, which has a Wiegand module, is known in the state of the art from the patent document DE 102 59 223 B3.
In this counting sensor, a permanent magnet moves relatively to the Wiegand module, which provides voltage impulses in defined time intervals as a function of the movement frequency.
A processing electronics detects the voltage impulse and determines both the movement direction of the permanent magnet and the position of the north pole and the south pole of the permanent magnet on the basis of the output signal of an additional sensor element and on the basis of the polarity of the voltage impulse. On the basis of these informations, the processing electronics determines a number of the revolutions of the permanent magnet and stores a corresponding value in a data storage.
The known counting sensor can be operated in an autonomous mode, in which no outside energy supply is available. In the autonomous mode, the processing electronics is supplied with energy, which the Wiegand module provides by the output of the voltage impulses. The energy provided by the Wiegand module is sufficient for the determination of said value of the number of the revolutions and for the storing process of the value in the data storage, provided an output of clean voltage impulses.
In the framework of the development activities of the present invention, it has been recognized that during the operation of the known counting sensor, due to certain movement sequences of the permanent magnet, a case may occur that the Wiegand module outputs rudimentary voltage impulses, which are in fact recognized, but which do not supply sufficient energy in order to be able to perform the storage process of said value. In this respect, errors of the stored value and a reduced accuracy of the counting sensor do result.